| blob | b7b31475c034f157cf44d06d1288c57792ab5cfd |
1 ;; -----------------------------------------------------------------------
2 ;;
3 ;; Copyright 1994-2008 H. Peter Anvin - All Rights Reserved
4 ;;
5 ;; This program is free software; you can redistribute it and/or modify
6 ;; it under the terms of the GNU General Public License as published by
7 ;; the Free Software Foundation, Inc., 53 Temple Place Ste 330,
8 ;; Boston MA 02111-1307, USA; either version 2 of the License, or
9 ;; (at your option) any later version; incorporated herein by reference.
10 ;;
11 ;; -----------------------------------------------------------------------
13 ;;
14 ;; comboot.inc
15 ;;
16 ;; Common code for running a COMBOOT image
17 ;;
19 section .text
21 ; Parameter registers definition; this is the definition
22 ; of the stack frame used by INT 21h and INT 22h.
23 %define P_FLAGS word [bp+44]
24 %define P_FLAGSL byte [bp+44]
25 %define P_FLAGSH byte [bp+45]
26 %define P_CS word [bp+42]
27 %define P_IP word [bp+40]
28 %define P_DS word [bp+38]
29 %define P_ES word [bp+36]
30 %define P_FS word [bp+34]
31 %define P_GS word [bp+32]
32 %define P_EAX dword [bp+28]
33 %define P_AX word [bp+28]
34 %define P_HAX word [bp+30]
35 %define P_AL byte [bp+28]
36 %define P_AH byte [bp+29]
37 %define P_ECX dword [bp+24]
38 %define P_CX word [bp+24]
39 %define P_HCX word [bp+26]
40 %define P_CL byte [bp+24]
41 %define P_CH byte [bp+25]
42 %define P_EDX dword [bp+20]
43 %define P_DX word [bp+20]
44 %define P_HDX word [bp+22]
45 %define P_DL byte [bp+20]
46 %define P_DH byte [bp+21]
47 %define P_EBX dword [bp+16]
48 %define P_BX word [bp+16]
49 %define P_HBX word [bp+18]
50 %define P_BL byte [bp+16]
51 %define P_BH byte [bp+17]
52 %define P_EBP dword [bp+8]
53 %define P_BP word [bp+8]
54 %define P_HBP word [bp+10]
55 %define P_ESI dword [bp+4]
56 %define P_SI word [bp+4]
57 %define P_HSI word [bp+6]
58 %define P_EDI dword [bp]
59 %define P_DI word [bp]
60 %define P_HDI word [bp+2]
62 ; Looks like a COMBOOT image but too large
63 comboot_too_large:
64 mov si,err_comlarge
65 call cwritestr
66 jmp enter_command
68 ;
69 ; Load a COMBOOT image. A COMBOOT image is basically a DOS .COM file,
70 ; except that it may, of course, not contain any DOS system calls. We
71 ; do, however, allow the execution of INT 20h to return to SYSLINUX.
72 ;
73 is_comboot_image:
74 and dx,dx
75 jnz comboot_too_large
76 cmp ax,0ff00h ; Max size in bytes
77 jae comboot_too_large
79 push si ; Save file handle
81 call make_plain_cmdline
83 call comboot_setup_api
85 mov cx,comboot_seg
86 mov es,cx
88 xor di,di
89 mov cx,64 ; 256 bytes (size of PSP)
90 xor eax,eax ; Clear PSP
91 rep stosd
93 mov word [es:0], 020CDh ; INT 20h instruction
94 ; First non-free paragraph
95 ; This is valid because comboot_seg == real_mode_seg
96 ; == the highest segment used by all derivatives
97 int 12h ; Get DOS memory size
98 shl ax,6 ; Kilobytes -> paragraphs
99 mov word [es:02h],ax
101 %ifndef DEPEND
102 %if real_mode_seg != comboot_seg
103 %error "This code assumes real_mode_seg == comboot_seg"
104 %endif
105 %endif
106 ; Copy the command line from high memory
107 mov si,cmd_line_here
108 mov cx,125 ; Max cmdline len (minus space and CR)
109 mov di,081h ; Offset in PSP for command line
110 mov al,' ' ; DOS command lines begin with a space
111 stosb
113 .loop: es lodsb
114 and al,al
115 jz .done
116 stosb
117 loop .loop
118 .done:
120 mov al,0Dh ; CR after last character
121 stosb
122 mov ax,di
123 sub al,82h ; Include space but not CR
124 mov [es:80h],al ; Store command line length
126 ; Now actually load the file...
127 pop si ; File handle
128 mov bx,100h ; Load at <seg>:0100h
129 mov cx,0FF00h >> SECTOR_SHIFT
130 ; Absolute maximum # of sectors
131 call getfssec
133 ; And invoke the program...
134 mov ax,es
135 mov ds,ax
136 mov ss,ax
137 xor sp,sp
138 push word 0 ; Return to address 0 -> exit
140 jmp comboot_seg:100h ; Run it
142 ; Proper return vector
143 comboot_return: cli ; Don't trust anyone
144 push enter_command ; Normal return to command prompt
145 jmp comboot_exit
147 ;
148 ; Set up the COMBOOT API interrupt vectors. This is also used
149 ; by the COM32 code.
150 ;
151 comboot_setup_api:
152 mov di,4*0x20 ; DOS interrupt vectors
153 mov eax,comboot_return ; INT 20h = exit
154 stosd
155 mov ax,comboot_int21 ; INT 21h = DOS-compatible syscalls
156 stosd
157 mov ax,comboot_int22 ; INT 22h = proprietary syscalls
158 stosd
159 mov ax,comboot_bogus
160 mov cx,29 ; All remaining DOS vectors
161 rep stosd
162 ret
164 ; INT 21h: generic DOS system call
165 comboot_int21: cli
166 push ds
167 push es
168 push fs
169 push gs
170 pushad
171 cld
172 mov bp,cs
173 mov ds,bp
174 mov es,bp
175 mov bp,sp ; Set up stack frame
177 call adjust_screen ; The COMBOOT program might have changed the screen
179 mov cx,int21_count
180 mov si,int21_table
181 .again: lodsb
182 cmp al,P_AH
183 lodsw
184 loopne .again
185 ; The last function in the list is the
186 ; "no such function" function
187 clc
188 call ax ; Call the invoked function
189 comboot_resume:
190 mov bp,sp ; In case the function clobbers BP
191 setc P_FLAGSL ; Propagate CF->error
192 popad
193 pop gs
194 pop fs
195 pop es
196 pop ds
197 iret
199 ; Attempted to execute non-21h DOS system call
200 comboot_bogus: cli ; Don't trust anyone
201 mov cx,err_notdos
202 push enter_command
203 jmp comboot_exit_msg
205 ;
206 ; Generic COMBOOT return to command line code
207 ; stack -> where to go next
208 ; CX -> message (for _msg version)
209 ;
210 comboot_exit:
211 xor cx,cx
212 comboot_exit_msg:
213 pop bx ; Return address
214 RESET_STACK_AND_SEGS AX
215 call adjust_screen ; The COMBOOT program might have changed the screen
216 jcxz .nomsg
217 mov si,KernelCName
218 call cwritestr
219 mov si,cx
220 call cwritestr
221 .nomsg:
222 jmp bx
224 ;
225 ; INT 21h system calls
226 ;
227 comboot_getkey: ; 01 = get key with echo
228 call vgashowcursor
229 call comboot_getchar
230 call vgahidecursor
231 call writechr
232 clc
233 ret
235 comboot_writechr: ; 02 = writechr
236 mov al,P_DL
237 call writechr
238 clc
239 ret
241 comboot_writeserial: ; 04 = write serial port
242 mov al,P_DL
243 call write_serial
244 clc
245 ret
247 comboot_getkeynoecho: ; 08 = get key w/o echo
248 call comboot_getchar
249 clc
250 ret
252 comboot_writestr: ; 09 = write DOS string
253 mov es,P_DS
254 mov si,P_DX
255 .loop: es lodsb
256 cmp al,'$' ; End string with $ - bizarre
257 je .done
258 call writechr
259 jmp short .loop
260 .done: clc
261 ret
263 comboot_checkkey: ; 0B = check keyboard status
264 cmp byte [APIKeyFlag],00h
265 jnz .waiting
266 call pollchar
267 .waiting: setz al
268 dec al ; AL = 0FFh if present, 0 if not
269 mov P_AL,al
270 clc
271 ret
273 comboot_checkver: ; 30 = check DOS version
274 ; We return 0 in all DOS-compatible version registers,
275 ; but the high part of eax-ebx-ecx-edx spell "SYSLINUX"
276 mov P_EAX,'SY' << 16
277 mov P_EBX,'SL' << 16
278 mov P_ECX,'IN' << 16
279 mov P_EDX,'UX' << 16
280 ret
282 comboot_getchar:
283 cmp byte [APIKeyFlag],00h
284 jne .queued
285 call getchar ; If not queued get input
286 and al,al ; Function key? (CF <- 0)
287 jnz .done
288 mov [APIKeyWait],ah ; High part of key
289 inc byte [APIKeyFlag] ; Set flag
290 .done: mov P_AL,al
291 ret
292 .queued: mov al,[APIKeyWait]
293 dec byte [APIKeyFlag]
294 jmp .done
296 ;
297 ; INT 22h - SYSLINUX-specific system calls
298 ; System call number in ax
299 ;
300 comboot_int22:
301 cli
302 push ds
303 push es
304 push fs
305 push gs
306 pushad
307 cld
308 mov bp,cs
309 mov ds,bp
310 mov es,bp
311 mov bp,sp ; Set up stack frame
313 call adjust_screen ; The COMBOOT program might have changed the screen
315 cmp ax,int22_count
316 jb .ok
317 xor ax,ax ; Function 0 -> unimplemented
318 .ok:
319 xchg ax,bx
320 add bx,bx ; CF <- 0
321 call [bx+int22_table]
322 jmp comboot_resume ; On return
324 ;
325 ; INT 22h AX=0000h Unimplemented call
326 ;
327 comapi_err:
328 stc
329 ret
331 ;
332 ; INT 22h AX=0001h Get SYSLINUX version
333 ;
334 comapi_get_version:
335 ; Number of API functions supported
336 mov P_AX,int22_count
337 ; SYSLINUX version
338 mov P_CX,(VER_MAJOR << 8)+VER_MINOR
339 ; SYSLINUX derivative ID byte
340 mov P_DX,my_id
341 ; For future use
342 mov P_BX,cs ; cs == 0
344 mov P_ES,ds
345 ; ES:SI -> version banner
346 mov P_SI,syslinux_banner
347 ; ES:DI -> copyright string
348 mov P_DI,copyright_str
350 comapi_nop:
351 clc
352 ret
354 ;
355 ; INT 22h AX=0002h Write string
356 ;
357 ; Write null-terminated string in ES:BX
358 ;
359 comapi_writestr:
360 mov ds,P_ES
361 mov si,P_BX
362 call writestr
363 clc
364 ret
366 ;
367 ; INT 22h AX=0003h Run command
368 ;
369 ; Terminates the COMBOOT program and executes the command line in
370 ; ES:BX as if it had been entered by the user.
371 ;
372 comapi_run:
373 mov ds,P_ES
374 mov si,P_BX
375 mov di,command_line
376 call strcpy
377 push load_kernel ; Run a new kernel
378 jmp comboot_exit ; Terminate task, clean up
380 ;
381 ; INT 22h AX=0004h Run default command
382 ;
383 ; Terminates the COMBOOT program and executes the default command line
384 ; as if a timeout had happened or the user pressed <Enter>.
385 ;
386 comapi_run_default:
387 push auto_boot
388 jmp comboot_exit
390 ;
391 ; INT 22h AX=0005h Force text mode
392 ;
393 ; Puts the video in standard text mode
394 ;
395 comapi_textmode:
396 call vgaclearmode
397 clc
398 ret
400 ;
401 ; INT 22h AX=0006h Open file
402 ;
403 comapi_open:
404 push ds
405 mov ds,P_ES
406 mov si,P_SI
407 mov di,InitRD
408 call mangle_name
409 pop ds
410 call searchdir
411 jz comapi_err
412 mov P_AX,ax
413 mov P_HAX,dx
414 mov P_CX,SECTOR_SIZE
415 mov P_SI,si
416 clc
417 ret
419 ;
420 ; INT 22h AX=0007h Read file
421 ;
422 comapi_read:
423 mov es,P_ES
424 mov bx,P_BX
425 mov si,P_SI
426 mov cx,P_CX
427 call getfssec
428 jnc .noteof
429 xor si,si ; SI <- 0 on EOF, CF <- 0
430 .noteof: mov P_SI,si
431 ret
433 ;
434 ; INT 22h AX=0008h Close file
435 ;
436 comapi_close:
437 mov si,P_SI
438 call close_file
439 clc
440 ret
442 ;
443 ; INT 22h AX=0009h Call PXE stack
444 ;
445 %if IS_PXELINUX
446 comapi_pxecall:
447 mov bx,P_BX
448 mov es,P_ES
449 mov di,P_DI
450 call pxenv
451 mov P_AX,ax
452 clc
453 ret
454 %else
455 comapi_pxecall equ comapi_err ; Not available
456 %endif
458 ;
459 ; INT 22h AX=000Ah Get Derivative-Specific Info
460 ;
461 comapi_derinfo:
462 mov P_AL,my_id
463 %if IS_PXELINUX
464 mov ax,[APIVer]
465 mov P_DX,ax
466 mov ax,[StrucPtr]
467 mov P_BX,ax
468 mov ax,[StrucPtr+2]
469 mov P_ES,ax
470 mov ax,[InitStack]
471 mov P_SI,ax
472 mov ax,[InitStack+2]
473 mov P_FS,ax
474 %else
475 ; Physical medium...
477 mov P_CL,SECTOR_SHIFT
478 mov al,[DriveNumber]
479 mov P_DL,al
480 mov P_FS,cs
481 mov P_SI,OrigESDI
482 %if IS_SYSLINUX || IS_MDSLINUX || IS_EXTLINUX
483 mov P_ES,cs
484 mov P_BX,PartInfo
485 %elif IS_ISOLINUX
486 mov P_ES,cs
487 mov P_BX,spec_packet
488 %endif
489 %endif
490 clc
491 ret
493 ;
494 ; INT 22h AX=000Bh Get Serial Console Configuration
495 ;
496 comapi_serialcfg:
497 mov ax,[SerialPort]
498 mov P_DX,ax
499 mov ax,[BaudDivisor]
500 mov P_CX,ax
501 mov ax,[FlowControl]
502 or al,ah
503 mov ah,[FlowIgnore]
504 shr ah,4
505 test byte [DisplayCon],01h
506 jnz .normalconsole
507 or ah,80h
508 .normalconsole:
509 mov P_BX,ax
510 clc
511 ret
513 ;
514 ; INT 22h AX=000Ch Perform final cleanup
515 ;
516 comapi_cleanup:
517 %if IS_PXELINUX
518 ; Unload PXE if requested
519 test dl,3
520 setnz [KeepPXE]
521 sub bp,sp ; unload_pxe may move the stack around
522 call unload_pxe
523 add bp,sp ; restore frame pointer...
524 %elif IS_SYSLINUX || IS_MDSLINUX || IS_EXTLINUX
525 ; Restore original FDC table
526 mov eax,[OrigFDCTabPtr]
527 mov [fdctab],eax
528 %endif
529 ; Reset the floppy disk subsystem
530 xor ax,ax
531 xor dx,dx
532 int 13h
533 clc
534 ret
536 ;
537 ; INT 22h AX=000Dh Clean up then replace bootstrap
538 ;
539 comapi_chainboot:
540 call comapi_cleanup
541 mov eax,P_EDI
542 mov [trackbuf+4],eax ; Copy from
543 mov eax,P_ECX
544 mov [trackbuf+8],eax ; Total bytes
545 mov eax,7C00h
546 mov [trackbuf],eax ; Copy to
547 mov [EntryPoint],eax ; CS:IP entry point
548 mov esi,P_ESI
549 mov edx,P_EBX
550 mov bx,P_DS
551 jmp replace_bootstrap_one
554 ;
555 ; INT 22h AX=000Eh Get configuration file name
556 ;
557 comapi_configfile:
558 mov P_ES,cs
559 mov P_BX,ConfigName
560 clc
561 ret
563 ;
564 ; INT 22h AX=000Fh Get IPAPPEND strings
565 ;
566 %if IS_PXELINUX
567 comapi_ipappend:
568 mov P_ES,cs
569 mov P_CX,numIPAppends
570 mov P_BX,IPAppends
571 clc
572 ret
574 section .data
575 alignb 2, db 0
576 IPAppends dw IPOption
577 dw BOOTIFStr
578 numIPAppends equ ($-IPAppends)/2
580 %else
581 comapi_ipappend equ comapi_err
582 %endif
584 section .text
586 ;
587 ; INT 22h AX=0010h Resolve hostname
588 ;
589 %if IS_PXELINUX
590 comapi_dnsresolv:
591 mov ds,P_ES
592 mov si,P_BX
593 call dns_resolv
594 mov P_EAX,eax
595 clc
596 ret
597 %else
598 comapi_dnsresolv equ comapi_err
599 %endif
601 section .text
603 ;
604 ; INT 22h AX=0011h Maximum number of shuffle descriptors
605 ;
606 comapi_maxshuffle:
607 mov P_CX,trackbufsize/12
608 ret
610 ;
611 ; INT 22h AX=0012h Cleanup, shuffle and boot
612 ;
613 comapi_shuffle:
614 cmp P_CX,(2*trackbufsize)/12
615 ja .error
617 call comapi_cleanup
619 mov cx, P_CX
620 push cx ; On stack: descriptor count
622 lea cx,[ecx+ecx*2] ; CX *= 3
624 mov fs,P_ES
625 mov si,P_DI
626 mov di,trackbuf
627 push di ; On stack: descriptor list address
628 fs rep movsd ; Copy the list
630 mov eax,P_EBP
631 mov [EntryPoint],eax ; CS:IP entry point
632 mov esi,P_ESI
633 mov edx,P_EBX
634 mov bx,P_DS
635 jmp replace_bootstrap
636 .error:
637 stc
638 ret
640 ;
641 ; INT 22h AX=0013h Idle call
642 ;
643 ;
644 ; *** FIX THIS ***
645 ; The idle call seems to have detrimental effects on some machines when
646 ; called from a COM32 context (WHY?) -- disable it for now.
647 ;
648 %if 0 ; def HAVE_IDLE
650 comapi_idle:
651 DO_IDLE
652 clc
653 ret
655 %else
657 comapi_idle equ comapi_err
659 %endif
661 ;
662 ; INT 22h AX=0014h Local boot
663 ;
664 %if HAS_LOCALBOOT
665 comapi_localboot:
666 mov ax,P_DX
667 jmp local_boot
668 %else
669 comapi_localboot equ comapi_err
670 %endif ; HAS_LOCALBOOT
672 ;
673 ; INT 22h AX=0015h Feature flags
674 ;
675 comapi_features:
676 mov P_ES,cs
677 mov P_BX,feature_flags
678 mov P_CX,feature_flags_len
679 clc
680 ret
682 ;
683 ; INT 22h AX=0016h Run kernel image
684 ;
685 comapi_runkernel:
686 mov al,P_DL
687 cmp al,VK_TYPES-1
688 ja .error
689 mov [KernelType],al
690 push ds
691 mov ds,P_DS
692 mov si,P_SI
693 mov di,KernelName
694 call mangle_name
695 pop ds
696 call searchdir
697 jz comapi_err
699 ; The kernel image was found, so we can load it...
700 mov [Kernel_SI],si
701 mov [Kernel_EAX],ax
702 mov [Kernel_EAX+2],dx
704 ; It's not just possible, but quite likely, that ES:BX
705 ; points into real_mode_seg, so we need to exercise some
706 ; special care here... use xfer_buf_seg as an intermediary
707 push ds
708 push es
709 mov ax,xfer_buf_seg
710 mov ds,P_ES
711 mov si,P_BX
712 mov es,ax
713 xor di,di
714 call strcpy
715 pop es
716 pop ds
718 %if IS_PXELINUX
719 mov al,P_CL
720 mov [IPAppend],al
721 %endif
723 call comboot_exit
725 .finish:
726 ; Copy the command line into its proper place
727 push ds
728 push es
729 mov ax,xfer_buf_seg
730 mov dx,real_mode_seg
731 mov ds,ax
732 mov es,dx
733 xor si,si
734 mov di,cmd_line_here
735 call strcpy
736 mov byte [es:di-1],' ' ; Simulate APPEND
737 pop es
738 pop ds
739 mov [CmdLinePtr],di
740 mov word [CmdOptPtr],zero_string
741 jmp kernel_good_saved
743 .error equ comapi_shuffle.error
745 ;
746 ; INT 22h AX=0017h Report video mode change
747 ;
748 comapi_usingvga:
749 mov ax,P_BX
750 cmp ax,0Fh ; Unknown flags = failure
751 ja .error
752 mov [UsingVGA],al
753 mov cx,P_CX
754 mov dx,P_DX
755 mov [GXPixCols],cx
756 mov [GXPixRows],dx
757 test al,08h
758 jnz .notext
759 call adjust_screen
760 .notext:
761 clc
762 ret
763 .error:
764 stc
765 ret
767 ;
768 ; INT 22h AX=0018h Query custom font
769 ;
770 comapi_userfont:
771 mov al,[UserFont]
772 and al,al
773 jz .done
774 mov al,[VGAFontSize]
775 mov P_ES,ds
776 mov P_BX,vgafontbuf
778 .done: ; CF=0 here
779 mov P_AL,al
780 ret
782 ;
783 ; INT 22h AX=0019h Read disk
784 ;
785 %if IS_SYSLINUX || IS_MDSLINUX || IS_ISOLINUX || IS_EXTLINUX
786 comapi_readdisk:
787 mov esi,P_ESI ; Enforce ESI == EDI == 0, these
788 or esi,P_EDI ; are reserved for future expansion
789 jnz .err
790 mov eax,P_EDX
791 mov es,P_ES
792 mov bx,P_BX
793 mov bp,P_CX ; WE CANNOT use P_* after touching bp!
794 call getlinsec
795 clc
796 ret
797 .err:
798 stc
799 ret
800 %else
801 comapi_readdisk equ comapi_err
802 %endif
804 ;
805 ; INT 22h AX=001Ah Cleanup, shuffle and boot to flat protected mode
806 ;
807 comapi_shufflepm:
808 cmp P_CX,(2*trackbufsize)/12
809 ja .error
811 call comapi_cleanup
813 mov cx, P_CX
814 push cx ; On stack: descriptor count
816 lea cx,[ecx+ecx*2] ; CX *= 3
818 mov fs,P_ES
819 mov si,P_DI
820 mov di,trackbuf
821 push di ; On stack: descriptor list address
822 fs rep movsd ; Copy the list
824 mov fs,P_DS
825 mov si,P_SI
826 mov edi,TrampolineBuf
827 mov al,0B8h ; MOV EAX opcode
828 mov cl,9
829 .maketramp:
830 stosb ; MOV opcode
831 inc ax ; Next register opcode
832 fs movsd ; immediate value
833 loop .maketramp
834 mov byte [di-5],0E9h ; Last opcode is JMP
835 sub [di-4],edi ; Make JMP target relative
837 mov dword [EntryPoint],trampoline_to_pm
838 xor bx,bx ; DS on entry
839 jmp replace_bootstrap
840 .error:
841 stc
842 ret
844 ;
845 ; INT 22h AX=001Bh Cleanup, shuffle and boot with register setting
846 ;
847 comapi_shufflerm:
848 cmp P_CX,(2*trackbufsize)/12
849 ja .error
851 call comapi_cleanup
853 mov cx, P_CX
854 push cx ; On stack: descriptor count
856 lea cx,[ecx+ecx*2] ; CX *= 3
858 mov fs,P_ES
859 mov si,P_DI
860 mov di,trackbuf
861 push di ; On stack: descriptor list address
862 fs rep movsd ; Copy the list
864 mov fs,P_DS
865 mov si,P_SI
866 mov di,TrampolineBuf
868 ; Generate segment-loading instructions
869 mov bx,0C08Eh ; MOV ES,AX
870 mov cl,6 ; 6 segment registers (incl CS)
871 .segtramp:
872 mov al,0B8h
873 stosb ; MOV AX,imm16 opcode
874 fs movsw ; imm16
875 mov ax,bx
876 add bh,8
877 stosw ; MOV xS,AX
878 loop .segtramp
880 ; Clobber the MOV CS,AX instruction.
881 mov word [di-22], 9090h ; NOP NOP
883 ; Generate GPR-loading instructions
884 mov ax,0B866h ; MOV EAX,imm32
885 mov cl,8 ; 8 GPRs
886 .gprtramp:
887 stosw ; MOV ExX,imm32 opcode
888 fs movsd ; imm32
889 inc ah
890 loop .gprtramp
892 mov al,0EAh ; JMP FAR imm16:imm16 opcode
893 stosb
894 fs movsd ; CS:IP
896 mov dword [EntryPoint],TrampolineBuf
897 jmp replace_bootstrap
898 .error:
899 stc
900 ret
902 ;
903 ; INT 22h AX=001Ch Get pointer to auxillary data vector
904 ;
905 comapi_getadv:
906 mov P_ES,ds
907 mov P_BX,adv0.data
908 mov P_CX,ADV_LEN
909 ret
911 ;
912 ; INT 22h AX=001Dh Write auxillary data vector
913 ;
914 comapi_writeadv equ adv_write
916 section .data
918 %macro int21 2
919 db %1
920 dw %2
921 %endmacro
923 int21_table:
924 int21 00h, comboot_return
925 int21 01h, comboot_getkey
926 int21 02h, comboot_writechr
927 int21 04h, comboot_writeserial
928 int21 08h, comboot_getkeynoecho
929 int21 09h, comboot_writestr
930 int21 0Bh, comboot_checkkey
931 int21 30h, comboot_checkver
932 int21 4Ch, comboot_return
933 int21 -1, comboot_bogus
934 int21_count equ ($-int21_table)/3
936 align 2, db 0
937 int22_table:
938 dw comapi_err ; 0000 unimplemented syscall
939 dw comapi_get_version ; 0001 get SYSLINUX version
940 dw comapi_writestr ; 0002 write string
941 dw comapi_run ; 0003 run specified command
942 dw comapi_run_default ; 0004 run default command
943 dw comapi_textmode ; 0005 force text mode
944 dw comapi_open ; 0006 open file
945 dw comapi_read ; 0007 read file
946 dw comapi_close ; 0008 close file
947 dw comapi_pxecall ; 0009 call PXE stack
948 dw comapi_derinfo ; 000A derivative-specific info
949 dw comapi_serialcfg ; 000B get serial port config
950 dw comapi_cleanup ; 000C perform final cleanup
951 dw comapi_chainboot ; 000D clean up then bootstrap
952 dw comapi_configfile ; 000E get name of config file
953 dw comapi_ipappend ; 000F get ipappend strings
954 dw comapi_dnsresolv ; 0010 resolve hostname
955 dw comapi_maxshuffle ; 0011 maximum shuffle descriptors
956 dw comapi_shuffle ; 0012 cleanup, shuffle and boot
957 dw comapi_idle ; 0013 idle call
958 dw comapi_localboot ; 0014 local boot
959 dw comapi_features ; 0015 feature flags
960 dw comapi_runkernel ; 0016 run kernel image
961 dw comapi_usingvga ; 0017 report video mode change
962 dw comapi_userfont ; 0018 query custom font
963 dw comapi_readdisk ; 0019 read disk
964 dw comapi_shufflepm ; 001A cleanup, shuffle and boot to pm
965 dw comapi_shufflerm ; 001B cleanup, shuffle and boot to rm
966 dw comapi_getadv ; 001C get pointer to ADV
967 dw comapi_writeadv ; 001D write ADV to disk
968 int22_count equ ($-int22_table)/2
970 APIKeyWait db 0
971 APIKeyFlag db 0
973 zero_string db 0 ; Empty, null-terminated string
975 ;
976 ; This is the feature flag array for INT 22h AX=0015h
977 feature_flags:
978 %if IS_PXELINUX
979 db 1 ; Have local boot, idle not noop
980 %elif IS_ISOLINUX
981 db 3 ; Have local boot, idle is noop
982 %else
983 db 2 ; No local boot, idle is noop
984 %endif
985 feature_flags_len equ ($-feature_flags)
987 err_notdos db ': attempted DOS system call', CR, LF, 0
988 err_comlarge db 'COMBOOT image too large.', CR, LF, 0
990 section .bss1
991 ConfigName resb FILENAME_MAX